Increasingly broadcasters are interested in generating fingerprints, or signatures, of audio, video or audio-visual content, and in comparing fingerprints or signatures of such content in one or more audio, video or audio-visual data files and/or at one or more positions in a transmission chain, or in parallel transmission chains for audio and video content.
Many different methods of obtaining fingerprints, or signatures, are known. The present invention seeks to provide a new signature and techniques for obtaining and using signatures that extend the suite of techniques available in the prior art. The signature of the present invention may be particularly suitable for applications in which a small signature size is required.